Having received numerous emails asking questions about which iSCSI target software offers which feature I’ve put together a sheet which tries to sum up the various features and editions of the different Windows iSCSI target software available.
This sheet might be missing features actually available in certain products, some features might not be available at all and so on. The reason for this disclaimer is that all vendors name their features differently so I’ve tried to sum it up by reading the information available. Some vendors have chosen not to post anything useful about their product, so a comparison is not possible in this case. In the case where no information have been found or I’m unsure if it’s available I’ve marked it n/a. If the information has been clear it’s either yes or no.
Protocol information
From Wikipedia: In computing, iSCSI (pronounced /аɪsˈkʌzi/), is an abbreviation of Internet Small Computer System Interface, an Internet Protocol (IP)-based storage networking standard for linking data storage facilities. By carrying SCSI commands over IP networks, iSCSI is used to facilitate data transfers over intranets and to manage storage over long distances. iSCSI can be used to transmit data over local area networks (LANs), wide area networks (WANs), or the Internet and can enable location-independent data storage and retrieval. The protocol allows clients (called initiators) to send SCSI commands (CDBs) to SCSI storage devices (targets) on remote servers. It is a popular storage area network (SAN) protocol, allowing organizations to consolidate storage into data center storage arrays while providing hosts (such as database and web servers) with the illusion of locally-attached disks. Unlike traditional Fibre Channel, which requires special-purpose cabling, iSCSI can be run over long distances using existing network infrastructure.
http://en.wikipedia.org/wiki/ISCSI
http://www.ietf.org/rfc/rfc3720.txt
Table of features / prices
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Different approaches
Of all the vendors in the comparison there are about as many approaches as vendors. FalconStor for example has made an ESX appliance, which means that if you’re not running ESX you have no use of their product. According to what I can understand from their site you can connect anything to it once it’s up and running though. DataCore has chosen to make “bundles” of their product which led me to not really understand what I need and when and for what. Microsoft sells their iSCSI-target through OEM vendors, so to get your hands on Windows Storage Server you’ll need to buy storage from Dell, HP, Fujitsu or any other vendor that sells Windows-based appliances. Nimbus free product MySan only runs on Windows 2003 SP1 for some odd reason. SP 2 is not supported according to their information. Both Starwind, iscsicake and istorage server from Kernsafe comes in different editions with various features available. This seems like the best approach since you can choose an edition with the features you need for a price you’re willing to pay.
Links to vendors
http://www.datacore.com
http://www.falconstor.com
http://www.iscsicake.com
http://www.kernsafe.com
http://www.microsoft.com/Windowsserver2008/en/us/wss08.aspx
http://www.nimbusdata.com
http://www.starwindsoftware.com
How to choose
Choosing an iSCSI target software for your Windows based environment there are a few things to keep in mind. Looking at the table there are a lot of different editions with a bunch of different features. If you’re looking to emulate tape libraries and replicate data it’s in the higher price range. Satisfied with one or two concurrent connections you can get away alot cheaper, this would put you in the testing range though since a few concurrent connections won’t do you any good in production. Writing a recommendation here is virtually impossible considering the number of features available and the different needs in different situations. You’ll have to analyze what you really need and base your decision on that.
If you need help evaluating your storage needs, either SAN or iSCSI-based I can be of service. You can contact me through the contact form and I’ll get you in touch with our sales people to book either a visit or a virtual meeting depending on where you’re based.
Have I missed any software for Windows? What features do you think are the most useful / useless? Have you bought a product that you can recommend or warn anyone about?
Hi Marcelo!
Take a look at http://www.nimbusdata.com/ for more information on Nimbus.
Dear Joachim, I can not download any link Nimbus Mysan available. Could you send me or help?
Thanks for the article, KernSafe has done lots of upgrades since the article created, such as:
VHD support;
CDP & snapshot;
mirroring;
Thin provisioning
Etc.
Hi Christian!
You cannot access the same disk from two different servers unless you run for example CSV (Cluster Shared Volumes) since NTFS is not a clusterable file system. There are others that provide this as a third party product, for example Sanbolic. There’s an article available at http://www.moundalexis.com/archives/000014.php on the same problem also. The problem you’re seeing is because only one of the server can own the volume at the same time, hence it won’t show up. It’s possible to connect to the same iscsi target with multiple servers though, but it won’t be usable. When you create a cluster this ownership is taken care of automatically depending on which node owns the resource. Hope that answered your question.
Hi Joachim,
Thank you for this insight. However, Im having a major problem with iSCSI and was wondering if you’ve heard of the same problem and possibly know the solution…
Scenario
x1 Physical Server running 2008R2 DataCenter
x1 Virtual Machine running 2008R2 Standard
x1 Virtual Machine running 2008 Storage
The two Virtual Servers are on the same Hypervcore 2008R2 machine.
I have Microsoft iSCSI Target 3.2 installed on the Storage Server and can connect from both the physical server and the virtual machine server.
However, when I create a folder on one of the Servers and then go to the other Server, the folder doesnt show.
If I run a chkdsk on the Server where it doesn’t show, it finds the folder as orphaned and then repairs it. Reopening up Explorer and browsing to the iSCSI disk, now shows the folder. Very confusing!
This problem also happens with Starwinds iSCSI Target.
Is this by design or am I missing something?
Many thanks for any input. Look forward to your answer.
Hi Rene!
Thanks for the information! I spent quite a time on your website trying to figure that out, my comparison is based on the information I could find. My focus is as you might know Windows-based software, hence my assumption about the ESX-applicance.
Will you develop a target software for Windows-based hosts in the future?
Dear Joachim,
you are not fully correct in the point that the NSS from Falconstor is only offered as an ESX VA. In fact, this is just one of the representations of the NSS product. Besides the ESX Virtual Appliance (VA), NSS is also deliverable as a Ready-to-use Storage Appliance (so Storage, HW and SW coming from Falconstor), or as a software which can be installed on a customer-provided physical hardware. We are vendor independent for the storage you want to use, which is one of our biggest advantages. The scaling of NSS goes from single NSS node up to an HA set with failover between the nodes. So, there is a lot more ways to use the product, than just a ESX VA. In fact, smaller customer environments or branch offices may want to deploy the NSS ESX-VA since it allows them to run all services on one box. But, as we all understand, the SPOF is the ESX in the branch office itself in such case, so such a setup only makes sense in a mesh of various locations where a core location receives replications from the branch offices and provides the failover nodes for the ESX-VAs in the branch offices. Supported platforms to install our product NSS (and turn this box into a NSS appliance) on, are currently RH Linux, Centos and Oracle Linux. See more details about the certified platforms on http://www.falconstor.com/en/pages/?pn=MatrixOS.
To deploy the storage services which are exported by NSS to the customer network, you can actually use anything that speaks ISCSI, FC, CIFS or NFS, but to be on the safe side it is worthwile to take a look at our certification matrix as well. If you like to have more information, I’d be happy to provide more. Please feel free to contact me directly. BR René Angenheister, Falconstor EMEA
Hi!
I would’ve liked to have every products feature listed, but the time it takes to install each product and test it fully is time I don’t have.
Most products support CHAP which seems to be the standard for iSCSI. As far as integration with VmWare goes I’m wondering what you’re after? One of the products can host VmWare image files as disks, that’s about as far as the product information goes.
Hi there! Good article, but I would add there some more advanced functions, like support of AD, VmWare Toolkit integration, etc. In anyway my own choice for last time is Starwind iSCSI.